Lithographic plate making apparatus



Dec. 11, 1945. .1. T. CAMPBELL LITHOGRAPHIC PLATE MAKING APPARATUS 2Shee'ts-Shee't 1 Filed Dec,

INVENTOR. J/I/VES TC/IMPBELL.

fwd w-mm Dec. 1 l, 1945.

J. T. CAMPBELL LITHOGRAPHIC PLATE MAKING APPARATUS Filed Dec. 31, 1942 2Sheets-Sheet 2 INVENTOR. Jfl/VES 7. CAMPBEL L Patented Dec. 11, 1945UNITED STATES PATENT Y oFFIc E j z LITHOGRAPHIC PLATE MAKING APPARATUSJames '1. Campbell, Detroit, Mich.

Application December 31, 1942, Serial No. 470,871

2 Claims.

This invention relates to apparatus for making lithographic plates andmore particularly to apparatus for processing lithographic plates fromdeveloped film suitable for lithography and multilith presses.

Heretofore various apparatus has been employed for accomplishing'thisprocess, entailing extensive floor space and numerous unnecessaryoperations, both of which the present invention has sought to eliminate.

It is the object herein to provide means for printing a developed filmon a sensitized metal plate and for fullyv processing the same for usein a printing press.

It is the object herein to provide in combination suitable filmdeveloping apparatus disposed within a dark room, and metal plateprocessing means forming a part thereof but preferably disposed outsidethe dark room.

It is the further object herein to provision said apparatus within asuitable housing disposed through and within a dark room wall, togetherwith. communicating means between the dark room and the exterior wherebythe developed film may be transferred for further processing outside ofthe dark room.

Other objects will be seen in the following specification and claimsdescribing the various elements and their combinations as illustrated inthe accompanying drawings of which- Fig. 1 is a front elevational viewof the entire printing and developing apparatus.

Fig. 2 is a right end elevational view of the same.

It will be understood that said drawings illustrate merely a preferableembodiment of the invention and that it is contemplated that otherembodiments are possible within the scope of the claims hereafter setout.

In the drawings Fig. 1 shows the plate making cabinet H which may beprovisioned with hinged doors if desired, though not shown, which isdisposed with its front surface flush with the partition l2separatingthe camera dark room l3 from the exterior room It for accessto said cabinet.

Said dark room normally contains the camera, has access to thetemperature controlled sink which is disposed within the top of thecabinet H, being divided into a developing bath section ii, a centralwash section It, and a section ll for containing a fixing solution.

Suitable means are employed for controlling the temperature of the sinkby heating or cooling whereby a uniform quality of work can be obtainedin the processing of exposed film.

A safety lamp I is indicated above the sink within the dark room ithaving two separately illuminated compartments covered with ruby andflashed opal glass. A ruby glass is used for illumination duringdeveloping of the exposed film,

while the clear glass illumination is used for inspecting the finishednegative after its development.

' An opening [9 is disposed below the safety light i 8 and through thepartition wall I2, whereby the developed film may be transferred fromthe dark room to the exterior room It for further processing andprinting upon a metal plate, suitable closure means being employed forsaid opening.

The developed negative is then examined and if opaquing is necessary asuitable translucent opaquing table is employed so that the negative maybe touched up where desired.

A blanket plate printing frame 20, later described in detail andoperation, hingedly mounted in cabinet H at points 2! is adapted to benormally positioned vertically within the cabinet, but also adapted tobe pivoted outwardly to the dotted line position indicated at 20' and20". Frame 20 consists of seamless square tubing to provide arectangular frame, with a resilient blanket member 22 secured upon itsinner surface, said blanket having a beading 23 forming a part thereofwhich extends around and adjacent the outside edge of the blanket forair sealmg engagement with the glass frame 24.

An intermediate plywood or other supporting base 25 is provisionedwithin the blanket frame 20 providing a yielding support for the blanketmember 22 and also limiting inward movement thereof. Said glass frame 24also constructed of seamless square steel tubing, preferably, with aglass plate secured therein, is suitably hinged at 26 to the blanketframe 20 whereby while said glass frame may move outwardly with itssupporting blanket frame, it may also be tilted up wardly with respectthereto.

Being so hinged the glass frame may remain in vertical position, and atthe same time outward movement of the blanket frame 20 is permitted tothe position indicated at 20' with a suitable slide bracket 21 limitingthe relative movement.

On the other hand both frames 20 and 24 may be swung outwardlytohorizontal positions on hinges 2|, and further glass frame 24 may beangularly elevated around its hinged connection 26 to permit access tothe blanket frame for printing of the sensitized metal plate in themanner hereafter described.

Aiter examination of the developed negative, if opaquing is desired, theblanket frame is moved outwardly to the position shown at 20, and thesliding opaquing table 28 normally disposed in horizontal positionwithin opening 3| in cabinet H, is slid outwardly on suitable runner andtilted downwardly to the position shown at 28', with its outer endresting upon the upper end of the outwardly tilted blanket frame asshown at 20'. 1

The opaquing table consists of a steel or wooden frame of the sizerequired with one piece of flashed opal and one piece of blue plateglass inserted into the frame. The inner end of the frame hasprovisioned thereon clasps 23 adapted for engagement with the pins 30 atthe outer edge of the opening 3| to thereby prevent the opaquing table23 from being pulled out completely from the cabinet and further toallow the table to be lowered to rest upon the upper edge of the blanketframe indicated at 20'.

Frames 20 and 24 form together a vacuum contact printing unit betweenwhich the sensitized plate and the negative are interposed, both framesbeing first pivoted to vertical position before printing.

The source of illumination therefor consists of a plurality of rows ofhorizontally arranged lamps 32 which may be turned on by a suitabletiming switch hereafter described.

However for opaquing work the source of light is the same i. e. thelamps 32, whereby illumina-.

tion passing through the glass frame 24 is supplied to the surface ofthe opaquing table shown in the position 28', whereby the negativethereon may be suitably opaqued or touched up where required.

After opaquing the negative the opaquing table 28 is then slid back intohorizontal position within opening 3| in cabinet II, and also theblanket,

frame is tilted back into vertical position.

A plate whirler 33 is encased in the drawer 34 within cabinet II, or maybe installed on a swivel table; but in any event is adapted to he slidor swiveled forward outside of the cabinet for receiving the metalplate.

Said metal plate is flowed or covered with a suitable sensitizer andthen returned to its initial position within the cabinet, where it isproperly whirled to evenly spread the sensitizer and to thoroughly drythe same upon the plate. Thereafter the whirler is brought forward toremove the plate, and immediately returned to its initial position outof the way within the cabinet. Also attached to plate whirler 33 is arheostat for variable speed, and an electric heating element to dry thesolution.

Th blanket frames 20 and 24 are lowered to horizontal position by meansof hinges 2| and. the glass section 24 is separately raised on itshinges 26 and held in position by the slide bracket 21. The metal plateis then placed on the blanket 22 and the negative properly positionedupon the now sensitized surface of said plate. The glass frame 24 isagain lowered until its glass portion contacts the rectangular beading23 thereby providing an air tight seal between the two frames.

A vacuum producing source generally indicated at 35 is provided withinthe cabinet with a suitable conduit 36 connected thereto andcommunicating with the inner surface of the blanket frame 20 whereby airbetween the two frames may be withdrawn causing the blanket member 22within the blanket frame 20 to tightly engage the glass frame and toalso bring the metal plate into contact throughout with the surface ofthe negative therein;

After the vacuum is applied between the two frames, 'both are raised toa vertical position with the glass frame being disposed directly infront of the lamps 32. Said lamps are then turned on by a suitableswitch for a suflicient time to obtain a print from the negative uponthe metal plate. Thereafter both frames are lowered to horizontalpositions, the glass frame opened and the plate removed. Both frames 20and 24 may then be again moved back tovertical position to be disposedout of the way and entirely within cabinet H.

The metal plate is then placed upon the ink-up table 31 and developingink applied thereto. The top of the ink-up table is made of Vitro-lite,marble, non-rust metal, or other similar material.

Referring to Fig. 1 a suitable working space A is provided intermediatethe ink-up table and portion 3 of the cabinet I I upon which thedeveloping containers li, l8 and I! rest. Illumination of this space isprovided by the lamp 38 depending downwardly from the portion B ofcabinet I I. Spac A within cabinet II also provides access to the platedeveloping sink 3! within which the printed plate after inking-up isplaced for water flushing thereon until fully developed. Afterdevelopment the plate is dried, processed and.

then it is ready to be used in a printing press for lithographicprinting.

The plate making sink is made of selected wood or non-rust metal, andhas provisioned adjacent its rear upper edge a suitable flushing pipe40, perforated throughout its length as indicated at 4| to provide acontinuous water supply cascading down over the printed metal platelying upon the inclined Water rack 42 within the developing sink 39.Water is supplied through the pipe 43 from a suitable exterior sourcefor fluid communication with flushing pipe 40, there being a suitablemanually operable quick acting gate valve interposed at 44.

An instrument panel board 45, shown in Fig. l on the front of cabinet llbetween the printing frame 20 and plate whirler 33, is exterior to thedark room l3 with an electric interval timer 46 for the vacuum printer.It is understood that for printing from the negative upon a sensitizedplate within the printing frames, that the lights 32 are on only for ashort predetermined interval. Timer 46 provides manual means forregulating this interval of exposure.

A three-way manual valve 41 is shown for engaging and releasing thevacuum from the vacuum source 35 to the blanket frame 20 through conduit36. It will be understood that vacuum is required only after the blanketframe 20 and glass frame 24 are brought together with the sensitizedplate and negative disposed therebetween. Valve 41 also permits a quickrelease of the vacuum after the printing operation by allowing air torush in between the blanket frame and the printing frame, whereby saidprinting frames may be quickly opened, saving considerable timeheretofore lost.

A manual switch 48 is shown on the panel board for operating vacuum pump35 as and when desired. Likewise a manual switch 49 is shown for turningon and off printing lamp 32 within the cabinet II which are disposed inparallel relation directly, behind the glass printing frame 24.

ing means. The refrigerator unit is generally indicated diagrammaticallyat 5| within the storage compartment 52 in the bottom of cabinet ii, andis suitably connected by conduits 53 to the flat refrigerator coils 54which are soldered or otherwise secured to the under surface of sink B,providing an intimate heat conducting contact therewith whereby atemperature regulated fluid may be circulated to maintain apredetermined temperature of the water within sink B within which thedeveloping and fixing trays are partially immersed.

A separate electrical heating cable 55, preferably a lead covered wire,is also provisioned in coils against the bottom surface of sink Bbetween and co-extensive with the refrigerator coil 54, where, bythermostatic control, the temperature of the water within sink B can beaccurately maintained.

Insulating material 56 preferably cork and rock wool is then provisionedentirely around sink B, being disposed within the compartment member 51.

The central wash tray is suppled continuously, when in use, with a freshwater source 58, there being an overflow stand pipe 59 within said trayIt for maintaining the level of water therein. Said stand pipe isthreaded into the extension pipe 60 which downwardly depends below trayIE to be removably inserted within the sink stand pipe 5 I.

Stand pipe 59 is removable permitting flushing and cleaning of tray it.Its extension 6|! is adapted to provide a fluid drain connection withthe sink stand pipe so as not to disturb the cooled water in sink B. Itwill be noted also that stand pipe Bi is removable permitting flushingout of sink B when desired.

A drain connecting pipe 63 is adapted for threaded connection with thesink drain pipe 62, pipe 62 extending through the insulating compartment55 for communication with a suitable sewer drain 53.

Thermostatic controls 64 and 55 are shown on instrument panel 45 foroperating and regulating the refrigerator and heating units respectivelywhereby the developing sink B may be constantly maintained at anydesired predetermined temperature. For instance in a warm climatethermostat control 64 may be set to warm the water within sink B toapproximately 65 degrees F., and so adjusted as to actuate therefrigerator unit if the temperature of the fluid sink B rises to, forexample 67 degrees F.

On the other hand in a cool or cold climate thermostat switch 65 may beset also for maintaining the water in sink B at approximately 65 degreesF., being set to operate when the temperature drops to approximately 63degrees F.

It will be noted that both thermostats are so coupled together that by asuitable shaft or lever a temperature adjustment of one automaticallyadjusts the other for the same temperature. This guarantees that onlyone unit, refrigerating or heating, will be operative at one time.Further such a coupling between the two thermostats eliminates thetrouble and difficulty of separately adjusting both. So arranged, anadjustment of one, causes an automatic temperature setting of the other.

The cabinet housing ll therefore provides a compact lithograph filmdeveloping and plate making unit, and is'intended essentially forconserving floor space, time, and numerous steps Heretofore any one ofthe units above described, as for instance the negative developin sink,or the plate developing sink, or the printing mechanism occupied thespace now occupied by the entire cabinet, effecting a space saving ofapproximately 80 percent. 'This feature is important particularly whenthe unit is employed on ships or upon or adjacent the battle field.

A storage compartment 66 is shown in Fig. 1 which may be accessible fromboth sides of the cabinet. An additional film storage compartment 6'! isshown within the lower portion of the cabinet ll accessible from thedark room.

It will be noted that the dark room partition or wall I! is built snuglyaround the sink so that while the film developing sink B is entirelywithin the dark room, the plate making units above described areaccessible from the room exterior thereto.

For one man operation all apparatus could be installed within housingcabinet H t open t. wardly below the front section of said sink butentirely within the dark room whereby all processing could beaccomplished therein conveniently.

It will be seen from the drawings that all apparatus above described isenclosed within the cabinet flush with either the front or rear thereofso that when not in use, suitable doors, not shown in the drawings, maybe closed to keep all apparatus clean, and further to present a neatappearing cabinet occupying a very minimum of space."

Having. described my invention, reference should now be had to theclaims which follow for determining the scope thereof.

I claim:

1. Apparatus for processing lithographic printing plates from developedfilm comprising a cabinet housing, a vertically disposed blanket framehingedly mounted and nested within said housing and adapted to bepivoted outwardly, a glass frame nested within said housing hingedlymounted on said blanket frame to tilt therewith, and with respectthereto, a bracket member interconnecting said frames for limitingrelative tilting movement, a vacuum producing source within saidhousing, a conduit connecting said source and the top surface of saidblanket frame adjacent said glass frame, a translucent opaquing tablehorizontally and slidably disposed within said housing adapted to tiltdownwardly angularly when withdrawn therefrom, said blanket frame beingadapted to tilt outwardly at an angle independent of said glass frame toform a rest, for the outer end of said opaquing table. i

2. Apparatus for processing lithographic printing plates from developedfilm comprising a cabinet housing, a vertically disposed blanket framehingedly mounted and nested within said housing and adapted to bepivoted outwardly, a glass frame nested within said housing hingedlymounted on said blanket frame to tilt therewith, and with respectthereto, a bracket member interconnecting said frames for limitingrelative tilting movement, a vacuum producing source within saidhousing, a conduit connecting said source and the top surface of saidblanket frame adjacent said glass frame, a translucent opaquing tablehorizontally and slidably disposed within said housing adapted to tiltdownwardly angularly when withdrawn therefrom, said blanket frame beingadapted to tilt outwardly at an angle independent of said glass frame toform a rest for the outer end of said opaquing table, latching means onthe inner end of said table, and means on said cabinet cooperable withsaid latching means adapted to limit outward movement of said table, atthe same time permitting tilting thereof.

JAMES '1. CAMPBELL.

